diff --git a/src/query/src/qTsbuf.c b/src/query/src/qTsbuf.c
index 7049143ddcbb391c470c73b3129c8c8b865ca8b6..408dcc9881e18ec733525d33b3a938f8735f8e16 100644
--- a/src/query/src/qTsbuf.c
+++ b/src/query/src/qTsbuf.c
@@ -493,10 +493,10 @@ void tsBufAppend(STSBuf* pTSBuf, int32_t id, tVariant* tag, const char* pData, i
 }
 
 void tsBufFlush(STSBuf* pTSBuf) {
-  if (pTSBuf->tsData.len <= 0) {
+  if (pTSBuf->numOfGroups <= 0) {
     return;
   }
-  
+
   writeDataToDisk(pTSBuf);
   shrinkBuffer(&pTSBuf->tsData);